Study On The Pathogenicity Of Ureaplasma Urealyticum Serotpye 1 Of Different Concentrations In Rabbits Model

Objective:To study the pathogenicity of Ureaplasma urealyticum serotype 1(Uu1) of differrent concentrations in rabbit model.Method:26 rabbits treated with oestradiol were randomly divided into 4 groups,including group A,B,C and D.Ureaplasma urealyticum serotype 1 with the concentration of 10~7copy/g(groupA),10~6copy/g (groupB),10~5copy/g(groupC) were inoculated intravaginally into all 8 rabbits of every group,while 2 rabbits of control group(groupD) inoculated sterile medium.They were detected Uu1 from cervical secretions by fluorescent quantitative polymerase chain reaction (FQ-PCR) at 1,3,7,14,21,28 days,observing tissues of cervix,endometria, fallopian tube by light microscope and cervical mucosa by scanning electron microscope.Result:(1)The total positive rates of Uu1 in three experimental groups showed a significant difference(P＜0.01),which were 47.9% (23/48),31.3%(15/48),16.7%(8/48).And the positive rate descended as the days of postinoculation lasting.The highest positive rates of three experimental groups were 100.0%(8/8),75%(6/8),37.5%(3/8)at 1d after inoculation,but the conlisation didn't persist at 28d.All rabbits of control group were negtive.(2)There was statistical difference in the quantity of Uu1 among experimental groups,the higher inocula of Uu1,the higher quantity conlisation.Their peak level were 1.48×10~7copy/g,6.61×10~6copy/g,2.34×10~5copy/g reached at 1d,but the FQ-PCR values reduced as the days of postinoculation lasting.(3) The pathogenicity rate of three groups were different at 28d,which were 62.5%(5/8),37.5% (3/8),12.5%(1/8).And group A,group B were significant higher than group C.None of control group was positive.Conclusion:(1) The positive rate,quantity and pathogenity rate among experimental groups are increased with the higher concentration of Uu11inoculated in rabbit model.(2) In rabbit model,the pathogenicity of Uu1 varies with the quantity conlisation in genital tract.When Uu1 FQ-PCR value not less than 10~6copy/g,it will cause to disease easily.(3) Combination in the rat model UU3 in the pathogenicity of the conclusion of the study shows that in animal models UU have a certain pathogenic.